<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        alert('你好！')
        document.write('我来了javascript !')
        console.log('它~会魔法吧~')
        let age = 18
        let num = 21
        let name = '张三'
        console.log('输出结果：',num,name)
        prompt('输入姓名')
        let = prompt
        document.write('刚才输入的姓名')
    </script>
</body>
</html>